Integration into qmail using qmail-scanner
SpamAssassin can be integrated into qmail system-wide using qmail-scanner.
This is actually quite easy. SA is auto-detected when you install qmail-scanner, and uses the spamd/spamc combo if available. Here is my configure line (sans private data):
$ ./configure --spooldir /var/lib/qmailscan --qmaildir /var/qmail --bindir /var/qmail/bin \ --qmail-queue-binary /var/qmail/bin/qmail-queue --admin firstname.lastname@example.org --domain example.com \ --notify none --local-domains example1.com,example3.com,some.other.domain.net --silent-viruses auto \ --lang de_DE --debug 1 --unzip 0 --add-dscr-hdrs 0 --archive 1 --redundant no --log-details \ --fix-mime 1 --scanners "verbose_spamassassin" --install 1
More info is available at http://qmail-scanner.sourceforge.net/ .
I get this after trying the above... What's the problem? The tests on TestingInstallation worked fine... spamc doesn't work?
Building Qmail-Scanner 1.25st... This script will search your system for the virus scanners it knows about, and will ensure that all external programs qmail-scanner-queue.pl uses are explicitly pathed for performance reasons. Continue? ([Y]/N) Y Searching ........ Something like spamc for SpamAssassin detected - but not correctly installed (didn't include a "X-Spam-Status: Yes" line in output) - ignoring...
After a little more research, it looks like this command is failing during the qmail-scanner configure step:
/usr/bin/spamc < ./contrib/spamc-nasty.eml